Method of and apparatus for sidetracking in deep-well drilling



' N. E SPERSON METHOD OF' AND APPARATUS FR SIDETRACKING IN DEEP WELL DRILLING Filed Sent.

Inventor.'

Wiel@ Emerson am V A, tys.

Patented May 8, 1923.

UNITED y STATES 'muts EsrERsON,

s ff-1",454,o48 PATENT formel-1.

OF HOUSTON, TEXAS, AssIeNOR To REED ROLLRBIT COMPANY, or HOUSTON, TEXAS, A CORPORATION or 'rExAsg'f l MET-HOD or AND APPARATUS FOR SIDRTRAOKING IN -DREP-.WLL`DRILLING- Animation mea september a9, 1921. 'serial No. 504,120.

To all 'whom t may concern.'

Be it known that I, NIELs EsrERsoN, a citizen of the United States, and a resident of Houston, in the county ot' Harris and State of Texas, have invented certain new and useful Improvements in Methods of and Apparatus for Sidetracking in Deep-VVell Drilling, of which the following is a specifi-l cation.

My invention is an improvement in the process known, in the art of Adrilling oil wells, as side tracking and it also concerns improvements inthe vapparatus by which the improved process is carriedout.

The invention is shown in the accompanying drawing in which the ligure represents a central vertical sectional view of the well bein drilled, the apparatus being shown part y in section'andpartly in elevation.

.20 In these drawings, l indicates the well casin which is let down into the. well as in or inary practice, and 2 indicates what is known as a whipstock consisting of a member tapering upwardly to a thin edge, and at its lower end bein thick enough to reach about two thirds of tv e way across the bore of the casing. This whipstock has a concave face 3. It is let down into the well casing to a point where the Obstruction long lhole throughl the side of the casing.

In this milling action, the milling tool by bearing on the concaved face4 of the whip- -stock is deflected laterally as it passes down along the inclined face and thus the cutting through the side of the well casing is etfected so that the drilling tool which is let down to continue drilling, after the milling tool is withdrawn, may follow this side track past the Obstruction and the drilling then can go on to the required depth. The hole out throughthe side Ofthe well casing is about as long as the whipstock, starting at a pointat or near the level of the upper end thereof and terminating at a point at or near the level of its lower end.

Ordinarily the hole out is very irregular exists in the well and it may be held in any and by reason of limitations necessarily imposed by the diameter of the well casing the hole is not of sufficient length to lavoid too great a bend in the drill stem, which is subsequently introduced, or to avoid bringing the side-of the stem against the ragged edge of the hole and cutting the stem in two.

By my process and apparatus, the wall of the casing at the top of the hole is Spread outwardly for some distance above the upper edge of the hole and one effect of this is the same as though the hole were enlargedupwardly to this extent, and furthermore the ragged edge of the wall at the upper part of the hole is directed outwardly in respect to its original position and cutting throughof the drill stem by it is avoided. After the hole-is cutthrough the casing and the milling tool has been withdrawn, I introduce the improved tool or apparatus which isl provided with a pilot 4 of any suitable form, such as a roller bit or a fishtal bit. This is carried by a stiff or rigid hollow stem 5 composed of sections which have There are three of these eamers, one, a,

near the lower drill head, another, b, at a suitable distance above a to come against the wall of the casing above the milled hole therein, when the. apparatus has been deflected to a suitable inclination by the bit bearing on the inclined face of the whipstock, and the thirdc, at a suitable distance above b to bearij'on the casin on the side thereof opposite'side in w ich the hole lies. Y

As' the pilot or the lower ramerpasses down along theV inclined face 'o'ffthe whipstock it will be deiected out through the hole cut in the casing, and the second.

reamer b will be brought to bear on the casing at a point above the hole therein, and the upper reamer c will bear on the opposite wall of the casing. As the drill progresses downwardly the reamer b heldrigidly by the stiff stem, and traversing an inclined pathv will press the wall of the easing outwardly, beginning at a point, say at X, some distance above the upper edge of the hole and will make a long pathway for the drill stem at a very low angle to the axis of the' casing so that the said 4stemwill be subjected to deflection only at this low angle departing but little from the straight line of the casing. Sharp bends are thus avoided and damage to the drill stem prevented.

Furthermore the spreading of the wall of the casing at thetop of the opening'directs the ragged edge of the opening outwardly in respect to the position and direction this ragged edge originally occupied so that the drill stem instead o being cut by this ragged edge will find a bearing surface consisting of the comparatively smooth interior of the casing wall.

l do not limit myself to the use of the number of reamers shown nor to the particular construction of these spaced apart elements.

The greatervthickness of the stem of the improved apparatus as compared with the thickness of an ordinary tubular drill stein will be observed by comparison with the portion of the stem shown at 8.

rI`he above specification is to be regarded in a descriptive sense, and not as limiting the invention to the particular features described and shown, the scope of the invention being, defined by the appended claims.

The sections ofthe well casing are held together by couplings which are of greater diameter than the casing and there is some clearance between the exterior of' the collars or couplings and the original wall of the well and expansion of the casing can take place suiicient for the .purpose described.'

Irl`hepipe or bar carrying the reamers is hollow and ushing water can pass therethrough to the cutters as in common practice.

When the ilot cutter and its reamer pass through the ole in the casing, the wall is expanded considerably. This is followed by the intermediate member which does further expanding of the wall under the control of the upper member'c which holds the intermediate member to its work and causes it to make a more gradual and a longer deflection of the wall than would be the case if the upper member were not used.

The second reamer may not bulge the casing much, and the pressure will be distributed between second and third reamers. Second reamer will enlarge the casing to the right, third reamer will enlarge the casing to the left.

The usual practice is to insert in the hole a milling` tool 'of a diameter just enough under the inside diameter of the casing to permit the milling tool readily to pass through the pipe. It, therefore, happens that when the milling tool, which has a bevi \elled nose, reaches the whipstock, it is immediately held against the casing at the opposlte side and begins to cut the same. 'llhe bevel on the end of the milling tool I the casing outwardly intacte starts about an inch and a half or two inches back from theend; the bevel is on a 45 angle. rllhe pilot cutter 4 at the bottom would be the samediameter as the body of the milling tool which is first introduced.

rlhe original cutting throu h the casing is performed by the first mil ing tool and after the milling tool has been withdrawn, the remainder ofthe entire drilling action ifs done by the improved tool and liushing Water goes down through this the same as in ordinary practice.

l claim: 1. The herein described method of sidey tracking in drilling oil wells consisting in cutting an opening through the wall of the casing and thereafter spreading the wall of at the up er end of ,said opening, substantially as described.

'2. The herein described method of side tracking in drilling oil wells consisting in cutting an opening through the wall of the casing and thereafter spreading the wall of the casing outwardly, beginning at a point above the upper edge of the openino` and progressively to said edge whereby said edge will be located out beyond the point it originally occupied. 3. A paratus for side tracking in drilling oil wel s, comprising a whipstock, a stem having a pilot at its lower end, and' an enlargement on the stem ata point above the pilot to press the wall of the casing outwardly beginning at a point above and extending to saidy opening when the pilot is deflected" by the whipstock.

4. Apparatus for side tracking in drilling oil wells, comprising a whipstock, a stem having a pilot at its lower end, and an enlargement on the stem at a point above the, ilot to press the wall of the casing out'- war ly beginning at a point above and eX- tending to said opening, when the pilot is deflected by the whipstock, and another enlargement above `that first mentioned to bear -on the opposite wall of the casing to that in which the opening is cut.

5. Apparatus for side tracking in drilling oil wells, comprising a Whipstock, a stem having a pilot at its lower end, and an enlargement on the Stemat a point above the pilot to press the Wall of the casing out-V wardly beginning at a point above and extending to said opening, when the pilot is deflected by the whipstock, said enlargement havin rollers.

6. lpparatus for side tracking in drilling oil we s, comprising a whipstock, a stein having a pilot at its lower end,and an enlargement on the stem at a point above the pilot to press the wall of the casing outwardly beginning at a point above and extending to said opening, when the pilot is deflected by the whipstock, and another enlargement above that rst mentioned to bear on the opposite wall of the casing to that in whichthe opening is cut, Iboth of said enlargements having rollers.

7. Apparatus for side tracking in drilling oil wells, comprising a whipstock, a stein having a pilot at its lower end, and an enlargement on the stem at a point above the pilot to press lthe wall of the casing outwardly beginning at a point above and extending to said opening, when the pilot isl deflected by the whipstock, there being an enlargement also at tbe pilot, and at a point above and apart `from the enlargement first mentioned.

8. Apparatus of the class described comprising a whipstock for defiecting a tool for side tracking, a steni portion of extra stiffness in respect to the main portion of the drill stem to which it is connected, a pilot at the lower end of said stiff stem, an enlargement at an intermediate portion of said stilll stem, and a second enlargement Ion the said stiff stem above and spaced apart from the enlargement first mentioned.

, 9. A Well drilling apparatus comprising a drill head,.a main drill stem. a stiffer stem interposed between the main, drill stem and the drill head and forming the connection between them and a pair of reamers on said stiff stem spaced apart one above the other, said stiffer stein being substantially non-flexible under conditions where the main stem would' be deflected, substantially as de.- scribed. v l

10. Apparatus for side tracking in drilling oil wells, comprising a Whipstock for deflecting a drill head through the side of the well casinga drill head having cutters, means above the cutters for expanding the wall of the 'casing at the upper end of the openin therethrough, and a drill stem, Substantia ly as described.

11.- Apparatus for side tracking in drill.-v

ing oil wells, comprising a whipstock for deflecting a drill head through the side of the Well casing, a drill head having cutters, means above the cutters for expanding the wall of the casing at the upper end of the opening therethrough, and a drill stem', said means being of a diameter greater than the orbit of outer edge of thecutters, substantially as described.

12. A well drilling apparatus comprisin -a' drill head, a Amain drill stem, a whipstoc forv dellecting the drill head laterally, and a substantially non-flexible stem connecting the drill head with the Adrill stem and carrying an enlargement above the drill head to bear 4on the Well casing for expanding the same above the lateral aperture thereof, substantially as described.

13. A lWell drilling apparatus comprising a drill stem, a stiller stem attached to the lower end of the drill stem and forming an extension thereof, a drill head at the lower end of the stifferstem and an enlargement on the stiffer stem at a point above the drill head and below the lower end of the ordinary stem, substantially as described.

In testimony whereo ,I aiix my signature.

y NIELS EsPERsoN. 

